What temperature kills yeast in starter?

Answered by Jason Smith

The temperature at which yeast in a sourdough starter dies is around 140°F (60°C). It’s important to note that this is a general guideline, as individual yeast strains may vary slightly in their tolerance to heat. However, it’s best to err on the side of caution and avoid subjecting your sourdough starter to temperatures higher than this.

Maintaining your sourdough starter at a comfortable room temperature is ideal for its health and development. This temperature is typically around 70°F (21°C). Yeast is most active and productive within this range, allowing your starter to ferment and rise properly.

If the temperature rises significantly above 140°F (60°C), the yeast in your starter will begin to die off. This can happen, for example, if you place your starter near a heat source or accidentally expose it to direct sunlight for an extended period. It’s important to be mindful of the environment in which you keep your starter to ensure its survival.

On the other hand, extremely low temperatures can also be detrimental to your sourdough starter. While yeast can tolerate slightly colder temperatures, it becomes less active and may eventually go dormant if exposed to very cold conditions. However, it’s worth mentioning that some sourdough starters have been known to survive freezing temperatures and revive when thawed. So, while it’s not ideal to subject your starter to freezing temperatures, it may still have a chance of survival.

To summarize, it’s crucial to maintain your sourdough starter at a temperature range of around 70°F (21°C) to ensure the yeast’s optimal activity. Avoid exposing it to temperatures above 140°F (60°C) as this will kill the yeast. Additionally, be cautious of extremely low temperatures, as they can slow down or even temporarily halt the yeast’s fermentation process.

In my personal experience, I once accidentally left my sourdough starter near a heated oven, and the temperature rose significantly. Unfortunately, this resulted in the death of the yeast in my starter, and I had to start from scratch. It was a valuable lesson learned, reminding me of the importance of temperature control when it comes to maintaining a healthy sourdough starter.

Temperature plays a crucial role in the survival and productivity of yeast in your sourdough starter. By keeping your starter at a comfortable room temperature and avoiding extremes, you can ensure its longevity and ability to produce delicious bread.